I have a 100gal tank thats been going for 4 years now and we have a Marineland canister filter that works great. I don't really see a need for it but I have been thinking of getting a sponge filter as a secondary filter for the tank. I do sometimes have a small problem with the nitrite and ammonia levels but it dosen't take much to get them back to normal. Should I go ahead and add one to the tank or not, what do you think?

I use one. The type I use is a power-spray fan type that powers a strong jet of water from above the surface providing excellent oxygenation .It sounds like you could do with increasing your bacterial population so I would go for it. Something like this perhaps?[image]

I was looking at getting a Hydro Pro V sponge filter (for up to 125 gallons) and just hooking it up to our air pump. I'm worried about the strong jet of water part, the canister filter we have puts out a strong jet of water. I notice that our goldfish only being around about 2 inches each have a hard time swimming near the canister output.

Is there anyway to slow the current? For example my spray bar on my filter I have facing the back of my tank to help with the current and in my snails tank I have some sponge in front of my internal filter outlet to help with the current

LOL, thanks scrivens for the video the funny thing is I watched this video right before I posted this question plus I watch alot of his videos. Thanks to this guy my husband now thinks he can build us an even bigger tank (HAHA we will see how that on goes). I think I will just order the Hydro sponge filter, I looked at my air pump last night and realized it is for up to 60 gallons which explaines why I never thought it put out enough air for our tank. So I will just order the sponge filter and a new air pump.

The current we kind of took care of, the canister filter came with a dvd on how to install it and they say to put the output hose and input hose in the middle of the tank. When I realized the current would be a problem for our fish I moved the output to the far left side of the tank so they would have more room to swim without swimming into the current. Good idea on adding sponge to the output, I can't believe I didn't think of it.